Vortilons for Long-EZs
January 1986
Due to the wide variety of workmanship, flying characteristics can vary considerably from one airplane to another, even though they may have been built from the same plans. We have been confident up until now that Long-EZs were pretty much immune from a main wing stall, if they were operated within the normal limitation of gross weight and CG. Recently we were surprised to learn of a stock Long-EZ that experienced a main wing stall. Admittedly this aircraft had been loaded to well over normal gross weight, but the fact that it occurred at all has led us to make the following change a mandatory one for all Long-EZs, regardless of which canard is installed.
All Lonq-EZs must have three vortilons installed as shown on the leading edge of each main wing. We have conducted rather extensive testing of vortilons and they definitely do add to the stall marqin of a swept wing. They have always been required when using the new R1145MS canard, they are now required even if you have the original GU canard installed. Probably the best way to install vortilons is to make them with a small flange on each side. Finish them through final paint (using your trim color is a neat idea) then glue them to the finished wing in the appropriate position using a small amount of clear RTV silicone.
We have included full scale patterns for each vortilon, as well as a plan view and front view showing the positions at which each vortilon should be installed. The main design requirements are that the vortilons are mounted so that they are vertical, relative to the aircraft in level flight, and that they are mounted parallel to B.L.0 or the centerline. They do not cant outboard or inboard. The vortilon itself should be made from a six ply BID solid glass layup. The flanges can be two plies of BID on each side of each vortilon.